RioRand 7-80V PWM DC Motor Speed Controller Switch 30A Potentiometer cableabout 15CM can be separated, with running stop brake function Suitable for long hours of work:Circuit optimization design,stable Adjust the motor smooth no noise no vibration,with power indication,wide duty cycle adjustment range Using imported high-voltage MOS tube, three pressure 100V high-frequency low-resistance capacitors, automotive fuses PWM frequency: 12KHZ